Molecular sieves can be widely used in various applications, and different applications often impose different requirements on the pore structure in the framework of the molecular sieve. There are four types of pore structures in the framework of molecular sieves: microporous, mesoporous, macroporous and ultra-macroporous: microporous molecular sieves have a pore diameter ranging from 3 Å to 5 Å, such as CHA, LEV, SOD, LTA, ERI, KFI; mesoporous molecular sieves have a pore diameter ranging from 5 Å to 7 Å, such as MFI, MEL, EUO, MWW, TON, MTT, MFS, AEL, AFO, HEU, FER; macroporous molecular sieves have a pore diameter of 7 Å, such as FAU, BEA, MOR, LTL, VFI, MAZ; and ultra-macroporous molecular sieves have a pore diameter greater than 7 Å. In these molecular sieves with different pore structures in framework, ultra-macroporous molecular sieves have broken the limits on the pore of molecular sieves, and have shown many advantages in improving the reactivity of macromoleculars, prolonging the life of molecular sieves and improving product selectivity, and are expected to be well applicable in the processing of heavy oils and the production of organic chemical raw materials.
Among the current 232 kinds of molecular sieves with a pore structure in framework, there are only 10 kinds of ultra-macroporous molecular sieves, mainly including three types: aluminum-phosphorus/gallium molecular sieves, such as AlPO-8 (AET, 14-ring, 7.9×8.7 Å), VPI-5 (VFI, 18-ring, 12.1 Å), Cloverite (-CLO, 20-ring, 13.2 Å), JDF-20 (20-ring) and ND-1 (24-ring, 10.5 Å); silicon-germanium/Gallium molecular sieves, such as OSB-1 (OSO, 14-ring, Si/Be=2, 7.3×5.4 Å), ECR-34 (ETR, 18-ring, 10.5 Å, Si/Ga=3), ITQ-37 (30-ring), ITQ-43 (28-ring), ITQ-33 (18-ring), ITQ-44 (18-ring), ITQ-40 (16-ring) SSZ-53 (14-ring) and SSZ-59 (14-ring); and silica-alumina molecular sieves such as UTD-1 (DON, 14-ring, Si/Al2=∞, 10×7.5 Å) and CIT-5 (CFI, 14-ring, 7.5×7.2 Å, Si/Al2=190).
In view of its good performance and application prospects, there is still a need in the art to develop more types of ultra-macroporous molecular sieves.